Electric fuse



Sept. 25 1923. 1,468,758

A. w. STEELE ELECTRIC FUSE Filed Dec. 5, 1919 .m II."

l nue nto@ Rmm.

@ggg- .mi 2S sponding to ,construction; Fig. 7

vannexed hereto in wh'pch Fi and partly in section o Patented Sept. 25, 1923.

UNITED STATES y 1,468,758 ra'raarrv orricr..

ARCHIE W. STEELE, F BLOOMFIELD, NEW JERSEY, ASSIGNOR TO WILFOBD J. HAW- KINS, OF MONTCLAIR, NEW JERSEY.'

ELECTRIC rusa Application led December 3, '1919. Serialv No. 342,225.

To Il whom t may concern Be it known that I, Anemia lV. STEELE, a subject of the King of Great Britain, residing at 1() Park Avenue, Bloomfield, inthe county of Essex, State of New Jersey, have invented certain new and useful Improvements in Electric Fuses; and 1 do hereby declare the following to be a. full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appei'ta'ins to make and use the same.

This invention relates to electric fuses and is directed to the provision of a fuse of an improved construction which may lbe manufactured at low (ost and which is more effective than'fuses of low cost as heretofore constructed in sup ressing the arc` which is -forined when a use is ruptured.

I have found that 'the danger of explosion and the emission of flame when a fusible link is ruptured may be greatly reduced by enclosing the central attenuated` portion of the fusible linkin a casing of insulating material which is filled. with an absorbent substance such as lplaster of Paris, particularly when the casing is provided with a plurality of transverse artition walls through which the fusible link extends, and by mounting the closin f casing within a tube of insulating material 'having caps'at its ends which are provided with slots through which the ends of the fusible link extend and pon which the ends of the link are secured by suitable screws. Y

'The construction of this type which I prefer to employ is illustrated in the drawings 1 'is a central longitudinal section o the use; Fig. 2 is a similar view,.the plane'of the settion being at right angles to that of Fig. 1 on line 2-2 of Fig. 1; ig. 3 is an end view of the fuse; Fig. 4 is a transverse section on lino 444 of Fig. 2; Fig. 5 is a view'fpartly in elevation the link with its Fig. 6 is a view correillustrating a modified is an end view of the construction shown in Fig. 6 and Fig. 8 is a view corresponding to Fig. 7 with the attaching screw removed. Referrin link is re erably in the form of a flat strip 9 whicli surrounding casing;

Fig. 1

fusible link with its en= to these drawings, the fusible' is reduced in cross-sectional area' at the middle. The major portion of the length of this fusible link is enclosed within a shell or casing 1() preferably made of paper which is curled to form a cylinder.

At the ends and at points iiitermediate the ends of this shell 10 are partition walls 11 extending across the shell 10 and each of these partition walls is provided with a slot corresponding in size to the erom-section of the link 9. The entire shell 10 is filled with structed as indicated in Fig.4 5 is mounted within a tube 13 of insulating material such as fiber. The ends of lthistube 13 are closed by end caps 14 preferably formed from sheet metal. These end caps and the coacting walls of the tube 13 are not threaded; instead the caps have a sliding fit upon the ends of the tube 13 but' when they are in position upon the ends of the tube they are held againstlrotation in any suitable mannervas by the provision of a pin 15 o n each endl cap extendingjnwardly and entering aslot 16 in the 'end of the tube 13.

The transverse walls of the end caps are provided with slots ythrough which the ends of the fusible link 9 extend and these projecting ends of the link are bent over upon the transverse walls of the end caps. Adj acent to the slot through which the ends of the link 9 extends is a threaded hole adapted to receive the threaded shank of a s^rew 17 whose head overlies the end of the link so as to hold the link in position as is shown in Figs. 1 and 3. The ends of the link pro, jecting beyond the heads of the screws 17 may have figures stamped on them to indi- 'cate the current carrying capacity of the fuse. Preferably the end caps are formed as indicated in Figs. 1 and 2 with the central portions of the transverse walls thereof sunk below the rim ortions so that the heads of the screws 17 do not projectbeyond the planes of the` rims.

With such a construction, removal of a IOL 'burned out link and substitution of a new one may be quickly effected, employing for the purpose no tool other than a screwdriver. It is only necessary to loosen the screws 17, remove the end -caps `14 by a sliding movement and then take out the link unit withits casing 10; a new link unit with its casing may then be inserted within the tube 13, the end caps 14 replaced with the ends of the link 9 extending through the slots therein, the ends bent over and the screws 17 tightened upon them.

Figs. 6, 7 and 8 illustrate a slightly modied construction. In this form the screws for securing the ends of the fusible link are inthe form of threadedl plugs 18 which fill the entire space within the countersunk ends of the end caps 19. The flanges at the edges of the end caps may be sotted as shown at 20, so that when the ends of the link 9 are bent over the transverse walls of the end caps, their ends will lie in these slots 20 as shown in Figs. 7 and 8 to disclose the figures stamped thereon.

I claim:

An electric fuse comprising the combination of a fusible link, a shell of insulating material surroundin the middle portion of the link, a filling within the shell, a. rigid insulating tube enclosing the shell 'and in close engagement with the wall thereof, end caps having a sliding lit upon the ends of the tube, screws entering threaded holes in the end caps and having their heads engaging the bent-over ends of the link to thereby hold thev fuse in assembled relation, and means for preventing relative rotation of thecaps and tube.

In testimonywhereof I affix my siffnnture.

ARCHIE w. sTEiaLE. 

